Sales of previously owned U.S. homes (which make up the majority of the real estate on the market) were running at a disappointing 4.77 million annual rate in June, according to the latest release from the National Association of Realtors. Lawrence Yun, the organization’s chief economist, blamed an unusual spike in contract cancellations. But whatever the reason, it’s a lousy number.

For one thing, it’s below expectations: Economists surveyed by Bloomberg News had been forecasting a 4.9 million annual rate.

Second, it’s below the 5 million annual sales pace that, in my mind, would be indicative of some sort of recovery. (To give you some context, at the height of the housing boom, home sales were running at a pace of just over 6 million per year).

It’s tough to read much into year-over-year comparisons, because the numbers in June 2010 were inflated by the first-time homebuyer tax credit to 5.23 million. But still, I’d like to see us on a 5 million pace, which we touched briefly earlier in the spring.

Homebuilders seem to have more confidence than buyers, as May housing starts hit a five-month high, according to Tuesday’s Commerce Department release. The month marked the first time in five years that more homes had been started than completed.

The buyers who hung in seem to be investors, with 29% of the transactions being all cash.

Perhaps as a result of vulture activity, median prices zoomed in two troubled markets. Miami-Fort Lauderdale’s median price was up 24.5% over the past year, while Phoenix’s was up 22.5%. By contrast, the relatively stable (but still hot weather) Dallas-Fort Worth metroplex was up 3.1%.

The Northeast got kicked in the teeth, with Philly-area median prices down 29.6% and New York metro down 17.7%.

Financing was a tough haul; interest rates have been bouncing around, and I can’t help but think that the spike in contract cancellations — 16% of NAR members reported that a sales contract was canceled in June, up from 4% in May, according to Yun — was due to a combination of tight credit and fear.

Assuming the debt ceiling brouhaha ends, it will be interesting to see if those factors change in the July numbers.